The International Council for the Exploration of the Sea (Ices) is an independent body of scientists which advises governments on north-east Atlantic fisheries issues.

It has told European Union governments that all cod fishing in the North and Irish seas, west of Scotland and the Skagerrak should be closed. EU fisheries ministers start talks in Brussels on 16 December on the crisis.

Exhaustive research

Ices says the cod stocks are so low there is a serious chance they will collapse if fishing is not suspended.

It believes fishing for other species which swim with the cod - like haddock, whiting, plaice and prawn - should also be suspended, unless there is proof that it is not harming the cod.

Cod are caught before they spawn

Dr Hans Lassen of Ices told BBC News Online: "We estimate there are 30-40,000 tonnes of spawning cod in the North Sea.

"You need an absolute minimum of 70,000 tonnes, and for security you should have about twice that. It's nearly 20 years since there were 150,000 tonnes.

"Our estimates are based on national catch statistics, reports from marine laboratories in the member countries, and studies by our own research vessels.

"We know that nothing in biology is exact, and there's obviously a difference between an estimate of this year's stock and the number of fish you may find next year.

"But the last four years have been about the worst we've ever seen for the cod.

"We accept a 20-30% margin of error. But even if you double our estimates, the cod are still in a very bad way.

"North Sea cod mature when they're about four years old. The boats are fully exploiting the three-year-olds, and the mortality among two-year-old fish is about half.

"As things are, these fish will follow the Grand Banks cod. When it will happen is a pure guess - but happen it will."

Surprise fall

The Fisheries Research Services (FRS) marine laboratory in Aberdeen, UK, says: "The loss of cod, a major fish predator, and the depletion of haddock, may have serious knock-on effects on the marine ecosystem and result in adverse changes to other marine life."

Fishing continues while fish vanish

The two FRS research vessels spent more than 500 days at sea taking samples last year, and FRS observers went on more than 120 commercial fishing trips to record total catch rates.

FRS also sampled more than 2,200 separate landings by fishing vessels, and measured more than 450,000 fish.

It provides data to Ices to help it to formulate its advice on fish stock management.

Dr Robin Cook, the FRS chief executive, told BBC News Online: "The main difference from previous years is that the spawning stock we found in the most recent estimate is much lower than we'd thought.

Continued decline

"Compared with the year before, we have another with a very small production of young fish.

"At the moment, it looks as if things aren't getting any better for the cod, yet the fishing effort remains very high.

"We can't say when they'll become commercially extinct - it could be two years, or three, or five.

"The number of fish does fluctuate a lot from year to year. But the overall trend is downwards."